Pair aboard state jet (5)
I believe the answer is:
spray
'jet' is the definition.
(I know that spray is a type of jet)
'pair aboard state' is the wordplay.
'pair' becomes 'pr' (abbreviation).
'aboard' is an insertion indicator.
'state' becomes 'say' (to state something is to say it).
'pr' inserted within 'say' is 'SPRAY'.
(Other definitions for spray that I've seen before include "Sprinkle water on - a small bouquet" , "Flower arrangement" , "Disperse in tiny drops" , "Aerosol efflux" , "Drench" .)